in-consistent sputtering Z
 

driving to work today, stopped for some coffee, and once I got back into the car and went to get on the freeway, the car began to sputter in-consistently (it would sputter, then act normal, then sputter again). at first I thought it was the 'slip' light, but this sputtering feels rougher than the VDC kicking in, and I also checked it by turning off VDC, and it still happened. Total mileage on car is 20K

-it occurs at idle, partial throttle, WOT
-it occurs at a varaiety of speeds (city, freeway)
-it occurs at a variety of RPMs (including idle)

I've recently added headers and a full exhaust system - no SES or check engine light.

**It feels like 1 or 2 of the cylinders goes out when the sputtering happens...I hope the new headers didn't burn through some of the wiring :confused: (today was the first time I drove for more than 1hr consistenty...maybe it finnaly got hot enough to do some damage)

other possible problems:
1) bad gas (I don't think this is it b/c the problem would be consistent)
2) bad/clogged fuel injector or fuel pump (again, I would assume it'd be consistent)


any thoughts?

thanks,
Peter


--it's still too dark to be able to see anything at the moment, I'm going to wait until lunch to get back out there and pop-the hood.

subscribed, i have the same problem as of yesterday

subscribed, I'm interested in seeing what this might be.

okay, just went out and poped the hood...

-all wiring looks good; no signs of melting, overheating, or pinched wires
-on start up, it had the problem at idle
- still sounds the same, like 1 or 2 cylinders are not working (kinda like a STI engine)
- listening to the engine run from the engine bay, the passenger side sounds like it has the problem (there's a 'ssh' sound that occurs with the RPM's)

I'm thinking that either a spark plug or fuel injector is messed up...I'll have to take things apart once I get home. I think I'll try to drive it home...if it's only 1 cylinder, it should be okay (since I don't have cats, I don't have to worry about clogging them up with unburned gas)

-Peter

just talked with my Dad about this...he's thinking that it might be a burned/warped valve. The headers and full exhaust could lean the engine out to the point where they warp. Since this happened just after I shut the engine down for a few minutes (to get coffee) and then started it back up, that heat cycle might have warped it.

Has anyone else heard of a Z warping a valve from headers, TP, full exhaust??? I really hope this isn't it!

-Peter

got it fixed!!! :casper: :casper: :casper: :casper: :casper: :casper: :casper:

after checking the sprak plugs and fuel injectors and resetting the ECU, I figured out what was wrong...from my previous nitrous set-up, I had tapped into the TPS (throtle postion sensor) wire for a control modul and had left the tapped wire connected for possible future use...the end of the wire had a plastic protector on it, but the metal end still stuck out past the plastic - after using duct tape on the connector, the problem went away.

so, the TPS wiring had a soft short, which would cause the throttle to not open all the way, or fluctuate in it's position.


I'm just glad it runs normally again!

-Peter

Woo-whoo!! :clap:

Glad to hear the problem was a quick and easy fix. You had me worried there for a little while.

Have you decided whether or not that those mods could warp things?

CRAP!!!! I had driven the car last night for about 20 mintues without any sign of the problem. Start the car up this morning, and it's back! It comes and goes just as before....did it when the car was cold and warmed up, freeway/city, high/low rpms, idle/partial/full throttle...this sucks.

I'm now thinking that this might be something to do with an ignition coil...it's gotta be something electrical.

**No, I don't think that my mods could cause a warped valve, but both my dad and I always assume the worst...

it looks like I might need to bring it into Nissan to get some of this stuff checked out - I don't have all the electronics to figure out what's working and what's not. The one good thing is that this morning, the SES light came on, so I'll go down to Pep Boys and figure out what code it is.

-Peter

okay, took off from work early to fix this...

I remembered that I had also tapped into the igntion timing for cylinder #1 (front passenger side) to get the RPM for the nitrous module...I had forgotten that I left the wire still attached (just like the TPS wire with the metal connector just sticking out farther than the plastic protective shealth)...tape that, go for a drive and it's perfect again...this time, I'll wait until tomorrow to say that it's fixed, but my fingers are crossed! :fingersx:

-Peter


*yesterday's solution didn't sit completely right with me b/c when I listened to the engine, it sounded like 1 cylinder was out on the passenger side...but the throttle closing would not cause that kind of sound...I think I just doubted my hearing when the problem went away. The solution today seems much more likley and probably - hopefully that's it.

Looks like you're gonna keep us in suspense. Hoping you have good news to report back.

Netko(Grabs popcorn....)

drove the Z into work today...no signs of the problem - hopefully that means I fixed it!

Wooo-whoo!! (again):clap:

good catch